Nonpyrolyzed Fe-N Coordination-Based Iron Triazolate Framework: An Efficient and Stable Electrocatalyst for Oxygen Reduction Reaction.

Pyrolyzed base-metal-based metal-organic frameworks (MOFs) with FeN coordination are emerging as nonprecious metal catalysts for electrochemical oxygen reduction reaction (ORR). However, surprisingly, nonpyrolyzed MOFs involving Fe-N coordination have not been explored for the ORR. This study concerns the catalytic performance of a semiconducting nonpyrolyzed iron triazolate framework (FeTa ) for ORR in alkaline electrolyte. The FeTa catalyst is studied as composites with different amounts of conductive Ketjenblack carbon (KB). The performance of these FeTa -x KB (x denotes the KB/FeTa weight ratio) composites by onset and half-wave potentials of ORR appears to be superior to most previously documented nonpyrolyzed MOFs. Characterization by elemental analysis, FTIR spectroscopy, XPS, and cyclic voltammetry suggest that N-Fe -OH sites at the surface of FeTa function as the catalytic active sites. This FeTa also shows very stable activity during ORR, as supported by accelerated durability test of the FeTa -x KB sample (20 000 cycles, ca. 90 h). The framework structure of FeTa remains intact during the durability test, which would help to explain its excellent catalytic durability. This would be the first study demonstrating efficient and stable ORR catalysis by a nonpyrolyzed Fe-N coordination-based MOF material.